1. Technical Field
This invention relates to a roller conveyer suitable for installation on a ceiling or floor, or built into shelf facility. The present invention further relates to a roller shaft support that is used for such a roller conveyer and is adjustably positionable at a desired point of use within a side frame of the roller conveyer.
2. History of Related Art
U.S. Pat. No. 5,582,286, issued Dec. 10, 1996 to Kalm, et al., discloses a conventional prior art structure for a roller conveyer. In accordance with this conventional structure, a conveyer section is configured by providing a plurality of linear or tapered drive/transfer rollers supported by and extending between a pair of longitudinally extending side rail housings. Articles to be transferred by the conveyer section move along a longitudinal conveyer path whose extent and direction is defined by the side rail housings and supported rollers.
To mount the individual drive/transfer rollers to the side rail housings, holes are typically formed in the wall of the side rail housing into which a respective shaft end of each roller is inserted. Generally speaking, the cross-sectional shape of each roller shaft end is polygonal. More particularly, a hexagonal shape is conventionally used, but other polygonal, circular, or elliptical cross-sectional shapes may alternatively be used. The hole formed in the wall of the side rail housing has a shape corresponding to that of the roller shaft. In order to allow for easy insertion and extraction of rollers from the side rail frame, holes on at least one side of the conveyer must be slightly larger than the shaft. To assist in the insertion process, the shaft on end of each roller is spring-loaded. The non-spring-loaded shaft end of the roller is first inserted (at an angle to the conveyer path) into the larger one of the holes in the rail housing. The shaft on the copposite, spring-loaded, end of the roller is then loaded by depressing the spring-loaded end, and the roller is moved into position between the side rail housings. Once aligned with the hole on the opposite side rail housing, the spring-loaded shaft end is released, thus completing roller installation.
During operation of a roller conveyer, the drive rollers are intermittently actuated in order to control the transport of articles along the conveyer path. This intermittent actuation causes the roller shaft to rock back and forth within the slightly oversized holes in the side rail housing. After repeated occurrences of actuation and rocking back and forth, a rounding-off of the polygonal, or other, shape of either (or both) the roller shaft, or the side rail hole occurs. Eventually, this leads to failure of the roller mounting system, requiring a complete replacement of the side frame. Therefore, a need exists for a more stable and failure-resistant roller shaft mounting arrangement.
Moreover, the use of holes formed in the side rail housings to support a plurality of drive-transfer rollers fixes the position, pitch and orientation of the rollers along the conveyer path. Each reconfiguration of the rollers along the conveyor path undesirably may require the forming of new holes in an existing side rail housing. In more drastic reconfigurations, the formation of the required number of new holes in an existing side rail housing may be too difficult to implement, thereby requiring completely new side rail housings. Alternatively, additional holes formed in an existing side rail housing may weaken the structural integrity of the side rail housing. Replacement of the side rail housing, then becomes the only alternative. Thus, the above-referenced roller conveyer structures do not easily support roller reconfiguration, for example, to accommodate changes in pitch or changes in roller diameter. There is, accordingly, a need for linear or tapered roller support brackets that can be installed, removed and replaced without requiring the formation of new holes in the side rail housing or without affecting neighboring brackets.
The present invention is directed to overcoming the problems set forth above. It is therefore desirable to have a roller mounting bracket that is not only adjustable as to longitudinal position along the side frame of a conveyor, but also is easily adjusted after installation and during service to maintain the bracket in tightly fixed position with respect to the frame so that biased retention of the roller shaft end is maintained to prevent wear of the retention aperture in the brackets, or fretting of the roller shaft end.